1. Field of the Invention
The invention relates to an electronic device and, more particularly, to an interface switching system for an electronic device.
2. Brief Description of Prior Developments
As electronic devices continue to become more sophisticated, these devices provide an increasing amount of functionality. Many of these devices include connector interfaces allowing for peripheral components to be connected to the device and/or communication to other electronic devices. Circular connectors have been the most commonly used contact for multiple audio devices, including microphones, headphones, line-level audio outputs as well as video outputs. The circular connector may be an analog 2.5 mm or 3.5 mm headset or headphone connector, for example.
Basic mechanical dimensions of the connectors are reasonably well defined in different industry standards. As a consequence of the large number of applications and lack of binding standards in audio and telecommunications, the actual number of electrical contacts and their use varies from application to application. One example is the Open Mobile Terminal Platform (OMTP) standard for the pin order within the connector. Referring now to a circular connector or connector plug 26 shown in FIG. 2, the OMTP standard configuration includes Ground (GND) signal connected to a pin (or contact area) 28, a microphone signal connected to a pin (or contact area) 30, a right audio output signal connected to a pin (or contact area) 32, and a left audio output signal connected to a pin (or contact area) 34. In CDMA phones the standard requirement is to connect the ground signal to the pin 28, the left audio output to the pin 30, the right audio output to the pin 32, and the microphone signal to the pin 34. In another commonly used configuration (or alternative pinout configuration) the microphone signal is connected to the pin 28, the ground signal to the pin 30, the right audio out signal to the pin 32, and the left audio out signal to the pin 34.
This incompatibility leads to several different consequences when connecting devices with connectors of differing standards. For example, some basic functions may be available, but full functionality of the device may be lacking (such as stereo or mono audio outputs work, but the microphone or video outputs are inoperable). In another example, the functionality of the device may be too limited for practical use (such as only one audio channel of a stereo headphone available). In yet another example, there may be no functionality whatsoever (such as no audio output or input, or strong interference signals in the headphones).
Accordingly, there is a desire to provide an improved electronic device interface system.